Patients are placed in sitting position and American society of anesthesiologists standard monitors attached. After skin preparation, draping, and local anesthetic infiltration, an epidural Tuohy needle is introduced into intervertebral space at the level of L3-L4 up to the interspinous ligaments ( nearly 2cm mark on the needle). Fig 1 A3-way stopcock is connected to the hub of Tuohy needle with the in-line port of the stopcock attached to an air-filled 10 ml syringe. Using a 75 cm extension tube set the side port is connected to the Pressure Gauge Manometer held by the assistant. The stopcock is turned so that the needle is in direct continuity with both syringe and pressure Gage manometer. The syringe is used to create a 30 mm Hg pressure reading on the manometer, the stopcock then is turned into "open" to manometer and Tuohy needle and "close" to syringe.